Freeze - freeze prevents you from doing anything (except for interacting with the menus, so you can exit the game, but you can't do things such as moving, casting spells, drinking potions etc, this is all disabled), your sprite doesn't animate in this condition either, while frozen attacks will always hit you. Only other players and allies can remove freeze from you (as you yourself obviously can't).
Poison - while technically like the vanilla poison (ie it drains life), it has two differences, first of all, poison will randomly induce hit recovery on the player while he/she is poisoned. Poison can also kill you (also inside towns, so beware). Most npcs (inc. free healers), can remove poison.
Chill - chill slows you down, the amount of speed you lose depends on your cold resistance (unlike vanilla IIRC, but it's been too long to be sure), while chilled, your chance to hit suffers and monsters have an easier time hitting you. Chill can be removed by many npcs (but not the free healers, as it's not a health problem
). *hint thawing potions are cheaper then asking a npc to heal you.Stun - stun basically has the same effect as freeze, but your sprite still animates, while stunned every hit induces hit recovery and you are also easier to hit. Stun is a regular side effect of battle, if you run low on stamina, strong hits may stun you, it is always wise to watch your stamina before rushing into a mob (that or drink a potion).
Slow - The slow target effect from vanilla, the effect now visibly shows on targets, (they become light blue, not dark blue like chill). Slow can dispell Haste (and vice versa, Haste can dispell slow), thus you can never be hasted or slowed at the same time.
Prevent Heal - This comes in three flavours (for life, mana and stamina), if you are afflicted by this, the respective pool cannot heal (but it can drop further).
Wounds - The open wounds effect from vanilla, the bleeding is now enabled on players (players can, unlike vanilla, bleed now, also as result of getting struck by a strong hit). The damage dealt by the wounds isn't level dependant, but depends on how severe they are (depends on the weapon used for the attack that causes the wounds).
Burn - burn is a stand alone damage type, and a (rare) side effect of some fire attacks, while burning, you are covered in a cloud of fire and leave a trail of smoke (see screenshot thread), burn is resisted by fire resistance (et al.)
Petrification - the result of stone curse (and other things like this), stonecurse is similar to Freeze (no interaction, no animation), however stonecurse actually makes you harder to hit and you take less damage from physical attacks. Can only be removed by Stone to Flesh spells or waiting until it wears off, it's best to have an ally with you (player or merc), that can remove the effect if you go into dangerous terrain (or use a scroll of protection from petrification etc).
Acid - acid is like poison, it damages your life over time and can induce hit recovery (although rarer), what acid does ontop of this, it errodes your equipment, and your equipment is more likely to shatter then normally (shatter, not break, which means its completely gone). Acid reduces maximum and current durability of items as well as defense. Some types of equipment are not prone to acid damage.
"Darkness" - a side effect of negative plane damage, it randomly dispells buffs that you may have active, and drains mana over time (think poison, but burning your mana pool). Negative Plane attacks have many other side effects, this is just a common one.
Fear - fear takes away control from your character, you will proceed to run around (or walk if stamina is drained out) until the effect wears off or you get to a distance from the source of fear. There are many ways to prevent this, as a rule of thumb, if your threat is higher then that of a unit, it wont be able to induce fear.
Silence - silence is an anti-magic effect, spells that need to be chanted cannot be used while silenced, this applies also to monsters (annoyed by some mage, try and silence them if you can).
Blood Mana - the only curse I will discuss here, in vanilla this thing is a bit lame, it's rather unpredictable there. In MetalStorm bloodmana will apply a percentage of the mana cost of a spell as damage to you, this damage is considered magical and can be resisted. The amount of resisted damage is added back to the mana cost (so the amount of damage you didn't take gets applied to the mana pool). Furthermore, bloodmana heals the unit who cursed you by the amount of damage you took (hint for pvp). As a final note, blood mana will get you killed, as it will not go away when you hit low hp (I still don't get why they didn't do this in vanilla (it goes away after you drop to <= 40 hp IIRC), after all Iron Maiden could always kill the poor melee chars...).
Level Drain - level drain is a semi-permanent effect (that is, it lasts until it is dispelled by a restoration spell), level drain can make you lose up to 50 levels (you will lose only 1 level at a time). This also means that life, mana and stamina boni from the lost levels are negated. In the experience routines your full level is considered, so you cannot use this to earn more exp or get beyond a max level or anything stupid like that. Level drain also effects spell levels, that is, your spells will be weaker by x levels you got drained. All effects of level drain are cured by a restoration spell. (the effects will carry over if you exit the game and re-enter).
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